But such approaches should be met with some suspicion in the context of QG. One issue is the quantization procedure itself. Take models with constraints, such as general relativity (GR), for instance. Should we solve the constraints then quantize, or quantize then solve the constraints? The two methods are not, in general, the same (see e.g., [1]}). Another issue is choosing which degrees of freedom to quantize in the first place. Historically this process has been guided by tight coordination between theory and experiment, allowing trial and error to supplement an incomplete understanding of the quantization process itself. But absent such help from experiment, a more fundamental understanding of quantization may be necessary to make progress.
